Electrophoresis Method For Simultaneous Determination Research Articles

Ultra‐rapid capillary zone electrophoresis method for simultaneous determination of arginine and ibuprofen

The combination of arginine and ibuprofen is widely used for pain relief with a faster onset of action than conventional ibuprofen. Therefore, the determination of both compounds in a single run is highly desirable for rapid quality control applications. This paper reports an ultra-fast method (100 injections/h) for simultaneous determination of arginine and ibuprofen using capillary electrophoresis with capacitively coupled contactless conductivity detection. The separation of arginine as cation and ibuprofen as anion was achieved using a background electrolyte composed by an equimolar mixture of 10mmol/L of 2-(cyclohexylamino) ethanesulfonic acid and boric acid with pH adjusted to 8.4 using potassium hydroxide. The limits of detections were 5.3 and 10.0 μmol/L for arginine and ibuprofen, respectively. The proposed method is simple, fast (one analysis every 35 s), environmentally friendly (minimal waste generation) and accurate (recovery values between 95 and 98%).

Determination of Commonly Used Excipients in Pharmaceutical Preparations by Microchip Electrophoresis with Conductivity Detection

In this study, a microchip electrophoresis method for simultaneous determination of three frequently used pharmaceutical excipients (methylparaben, propylparaben and erythrosine) was described. Anionic zone electrophoresis (ZE) separations were performed on the microchip with contact conductivity detection using a high pH buffer (9.8). Sufficient resolution of the analytes (≥ 2.6) was achieved by 1 mmol L−1 β-cyclodextrin added to the buffer. Adsorption of the analytes on the walls of a poly(methylmethacrylate) microchip was suppressed by adding 1 mmol L− 1 sulfate to the sample. The LOD values for the excipients ranged from 0.5 to 11.1 µmol L− 1. High repeatability of the migration times of the analytes in model (< 2.9% RSD) and real pharmaceutical (< 4.1% RSD) samples was reached on the microchip. Peak areas of the analytes in all analyzed samples were characterized by RSD values ranging from 0.4 to 5.7%. The ZE method was successfully applied to the analysis of pharmaceutical syrups after a simple pretreatment (centrifugation and dilution), and gave recoveries of the analytes in the range 86.1–96.6%. The results showed a good agreement with those obtained by CZE with UV detection (254 nm) at 95% confidence level.

A bi-end injection capillary electrophoresis method for simultaneous determination of 37 cations and anions in beers.

Capillary electrophoresis (CE) is excellent at separating all the ions in a sample but is rarely used as a result of its detection issue and easy loss of very fast ions by common one-end injection methods. Herein we propose a newly developed method aimed at simultaneous determination of positive and negative ions with a home-made CE device, featuring bi-end injection and contactless conductivity detection at the middle. By simply using 2.5M acetic acid as a running buffer, the method can separate 37 ions (3 inorganic anions, 8 inorganic cations, 10 biogenic amines, and 16 amino acids) per run, with linearity between 10 and 2000μM (R2 > 0.99), limit of detection of 1.0-16.6μM, and limit of quantification of 2.3-31.7μM. The recovery measured by spiking standards into samples at high, middle, and low levels was between 73% and 110%. The intra- and interday repeatability of the 37 analytes ranged from 0.69% to 8.97% and from 0.68% to 11.04%, respectively. The proposed method was evaluated by analysis of 21 beers and, in addition to acquiring the concentration information, the brands of the tested beers were distinguished. This method is of high throughput, fast, and cost-effective. It could be a promising tool for ionomic analysis. Graphical abstract ᅟ.

A sample stacking-capillary electrophoresis method for simultaneous determination of nitrate and thiocyanate ions of ultra-heat-treated milk samples

Ultra-heat-treated (UHT) cow milk is mostly consumed in Turkey. Heating milk can cause some chemical and biochemical changes that affect different components of milk. However, studies on the constituents of UHT milk are scare. In the present study, nitrate and thiocyanate contents of commercial UHT~whole cow milk were determined simultaneously by sample stacking-capillary electrophoresis. The best separation of nitrate and thiocyanate ions was performed by reducing the electroosmotic flow at pH 4.0 using 30 mM formic acid and 30 mM sodium sulfate containing separation electrolyte. Analysis was completed in less than 3 min. The limits of detection obtained at a signal-to-noise ratio of 3 for nitrate and thiocyanate were 0.03 mg/L (0.48 μ role=presentation> μ μ \mu mol/L) and 0.06 mg/L (1.03 μ role=presentation> μ μ \mu mol/L), respectively. The nitrate concentration in commercial UHT milk samples ranged between 0.20 and 1.50 mg/L (3.23-24.20 μ role=presentation> μ μ \mu mol/L) and the thiocyanate ion concentration ranged between 0.41 and 0.67 mg/L (7.06-11.55 μ role=presentation> μ μ \mu mol/L).

Development and Validation of Capillary Electrophoresis Method for Simultaneous Determination of Six Pharmaceuticals in Different Food Samples Combining On-line and Off-line Sample Enrichment Techniques

A rapid and highly sensitive capillary electrophoresis method was developed combining on-line and off-line sample enrichment techniques that are capable to determine six widely used pharmaceuticals, viz. amoxicillin, carbamazepine, diclofenac, indomethacin, ibuprofen, and paracetamol from various food samples. A new sample preconcentration technique, i.e., in situ aggregated microextraction, was utilized to extract the analytes from various food samples. The process was carried out by the formation of aggregate phase in situ in the aqueous sample by ion association between oppositely charged surfactants, viz. Tiron® and cetyltrimethylammonium bromide. The separation and quantification of analytes were carried out in micellar electrokinetic chromatography mode at -20 kV. In short, the uncoated fused silica capillaries were filled with 80 mM phosphate buffer solution (pH 6.0) to act as leading electrolyte, and the samples were dissolved in 100 mM borate buffer and injected by electrokinetic mode applying -10 kV for 600 s. The method showed good linearity in between 0.06 and 50 µg/L for all six pharmaceuticals. Good repeatability and recoveries were obtained for all analytes in the range of 94.45–106.32% using optimized experimental conditions. The limit of detection ranged from 0.02 to 0.08 µg/L, and the limit of quantification ranged from 0.06 to 0.25 µg/L for six pharmaceuticals. The sensitivity of the developed micellar electrokinetic chromatography method was increased about 2500-folds compared to conventional capillary zone electrophoresis method. Finally, the developed analytical procedure was applied successfully for the detection of selected pharmaceuticals in fruits, urine, and river water samples.

Simultaneous analysis of Cu and Pb as ABEDTA complexes in Rhizoma coptidis by capillary electrophoresis coupled with solid phase extraction

Abstract A novel capillary electrophoresis method for simultaneous determination of Cu and Pb has been developed in this paper. Cu(II) and Pb(II) ions were reacted with ABEDTA to form complex to achieve an ideal sensitivity of heavy metal complexes. The digestion solution of Rhizoma coptidis drug sample was purified by neutral Al 2 O 3 column chromatography and the chromatographic behavior of metal–L complexes was investigated. The calibration curve was linear in the range of 5–60 μg/mL for Cu 2+ and 5–25 μg/mL for Pb 2+ with the correlation coefficients 0.9970 and 0.9972 for each ( n = 5). The average recoveries were 86.2% for Pb and 90.1% for Cu, while the relative standard deviations were 5.1% and 3.6% respectively. The method was successfully applied to determine Cu and Pb in R. coptidis drug samples.

A validated capillary electrophoresis method for simultaneous determination of ezetimibe and atorvastatin in pharmaceutical formulations

A simple, precise, and sensitive capillary electrophoresis technique coupled with a diode array detector has been developed for the separation and simultaneous determination of ezetimibe and atorvastatin in pharmaceutical formulations. Separation of both ezetimibe and atorvastatin was achieved utilizing fused silica capillary (58cm×75μm ID) and background electrolyte solution that consisted of phosphate buffer (2.5mM, pH 6.7): methanol (70:30 v/v). The proposed method was validated by testing its specificity, linearity, precision, accuracy, recovery, and detection limit/quantitation limit values. The method was linear over the range 2.5–50μg/ml for ezetimibe (r=0.9992) and 1–100μg/ml for atorvastatin (r=0.9999). Within-day and between-day RSD for ezetimibe and atorvastatin were ⩽5.6% and ⩽2.9%, respectively. The detection limit was 0.07μg/ml for ezetimibe and 0.06μg/ml for atorvastatin. The validated method was successfully employed for the determination of ezetimibe and atorvastatin in tablets with no interfering peaks from common pharmaceutical excipients. The percentage recoveries of the two drugs from their tablets were 99.80±1.76 and 100.19±1.83, respectively.

Application of a capillary electrophoresis method for simultaneous determination of preservatives in pharmaceutical formulations

Preservatives are used to protect pharmaceutical formulations from microbial attack during the period of administration to the patient. Because of their biological activity, preservatives have to be identified and assayed according to the same rules as apply to active components. A number of methods for separation of preservatives are reported, to account for the heterogeneity of their chemical structures. A capillary electrophoretic method was devised for simple and simultaneous qualification and quantification of the preservatives most often included in pharmaceuticals, such as benzyl alcohol, parabens, phenol, m-cresol, chlorobutanol, thimerosal. After systematic method development, the electrophoretic conditions were defined as: 50 mM borate buffer pH 9.0 containing 20 mM SDS. Separations were performed at a temperature of 20 degrees C and with detection at 214 nm. Preservatives under examination can be analyzed within a 10 min run. The method was successfully validated and applied to the determination of preservatives in a number of pharmaceuticals. Results from the CE method were compared with those from reference methods.

Capillary electrophoresis method for simultaneous determination of penicillin G, procaine and dihydrostreptomycin in veterinary drugs

Capillary electrophoresis method for identification and simultaneous determination of procaine, dihydrostreptomycin and penicillin G, present in multiantibiotic veterinary preparations, was elaborated. The influence of pH (5.0–9.75) and concentration of disodium tetraborate decahydrate in running buffers (0.02–0.1 M) as well as temperatures (25–40 °C) on separation efficacy were analyzed. For quantitative analysis, 0.08 M borate buffer (pH 8.0) at 35 °C and 15 kV were chosen. Method was validated, selectivity, precision, linearity, LOD, LOQ, accuracy and specificity of capillary zone electrophoresis (CZE) were evaluated.

A reproducible, simple and sensitive high-performance capillary electrophoresis method for simultaneous determination of capreomycin, ofloxacin and pasiniazide in urine

Separation and determination of capreomycin (Cp), ofloxacin (Oflx) and pasiniazide (Ipa) in urine by high-performance capillary electrophoresis (HPCE) with 280 nm detection have been studied systematically. The calibration lines were linear in the range of 0.5∼50 mg l −1, and the detection limits ( S/N=3) were 0.15, 0.20 and 0.10 mg l −1 for Cp, Oflx and Ipa, respectively. The recoveries for these materials from urine were higher than 93.5%. The accuracy and intra- and inter-day reproducibility of Cp, Oflx and Ipa were determined with satisfactory results. This method was successfully used for determining Cp, Oflx and Ipa in human urine.